The wife card is never valid, IMO. Yes...each guy has his own thing going in his respective marriage. But for me, I get what I want and my wife gets what she wants. Do we get pissed off sometimes? Sure. But we love each other enough that it's forgotten a day later. When I tell somebody I would buy a machine but my wife would kill me, that's just me knowing that the particular purchase I'm considering might be a little over the top. I don't TRY to induce stress in my wife. Being married to me is bad enough.
If you ever meet me (and let's hope you don't), ask me how I've played the cancer card. (My family gets cancer like there's a fire sale on terminal diseases.) It's f**king horrible...but it works.